Download - Introduction Into Automotive Electronics Design

Technical Center Krakow

December 3rd, 2008

Introduction into

Automotive Electronics Design

2Delphi Proprietary www.delphikrakow.pl

Agenda

• Introduction

• Requirements Definition and Design Constrains

• Project Life Cycle and Electrical Design Flow

• Product Definition

• Design Work Products

• Component Selection

• PCB Layout

• Verification

• Validation

• Lab Tour

• Questions & Answers

• EMC in Details


Evacuation Protocol


Introduction

• This presentation is about:

- How we design and test automotive electronic devices– Why it is not easy?

– Why it is relatively expensive?

– Why it takes time?

and more…


Divisions and PBUs

Electrical/ Electronic Architecture

Electronics & Safety

Powertrain

Steering

Thermal

Electrical/Electronic Distribution SystemsConnection Systems

Electrical Centers

Controls and SecurityEntertainment and Communications

Safety

Gasoline EMSDiesel EMS

Fuel management and Evaporative Canisters

Half ShaftsSteering Systems

Ventilation and Air ConditioningCooling Systems

Delp

hi

Ele

ctr

on

ics G

rou

p

Present at TCK

E/EA

Electronics & Safety (DEG)

Powertrain


Requirements Definition

Car MakerCar MakerCar MakerCar Maker

End UserEnd UserEnd UserEnd User• SecuritySecuritySecuritySecurity

•PerformancePerformancePerformancePerformance• LookLookLookLook

• FunctionalityFunctionalityFunctionalityFunctionality

• Components definitionComponents definitionComponents definitionComponents definition• RequirementsRequirementsRequirementsRequirements

• Technical SpecificationTechnical SpecificationTechnical SpecificationTechnical Specification• ComponentComponentComponentComponent

• CarCarCarCar

MechanicsMechanicsMechanicsMechanics ElectronicsElectronicsElectronicsElectronics SoftwareSoftwareSoftwareSoftware

SupplierSupplierSupplierSupplierSystemSystemSystemSystem

TestsTestsTestsTests


Design Constrains

• Extremal environmental conditions– Thermal schoc: -40/+85.. +125 °C

– Overvoltages

– ESD

– Vibrations

– Humidity

– Drops (ex. at car production line)

• Volume– 100k..1000k pcs./year

– Variants management

– Price competitive

• High reliability– Zero defects at End Of production Line

– Product lifetime: 10..15years

• Safety– Behavior on failures

– Safe for people and for car

Why?

For money...


Project Life Cycle

Quote Plan & Design Validation Production

Customer seeksfor potential

product supplier

Initial requirements and

project timing

Price, technical

capabilities, production

terms

Initial schematic, BOM,

requirements

Prototypes

Production

documentation

Supplier B

Supplier C

Model Year changes,

price reduction


Electrical Design Flow

Electronics & Safety

Product Definition

Product Definition

Electrical Design

Electrical Design Layout DesignLayout Design

HardwareVerification

HardwareVerification

PeerReview

PeerReview

CustomerRequirements

ManufacturingRequirements

Delphi DesignStandards

QualityGates

QualityGates


Product Definition

• Customer requirements (CDML)– Set of all features and functions for the product

– Electrical Specification (12/24/42V network, EMC)

– Environmental (Mechanical, Climatic, Chemical)

• Delphi Design Standards (DDS)– Know-how and good practices collection

• Manufacturing requirements– Manufacturing site specific requirements relevant to its technological

capabilities

• Requirements review– Identify gaps and coherence

– Check if implementable, testable and manufacturability

– Example: implement blinkers functionality -> need load specification, timings, what diagnostics is desired


• Customer’s black list

• Customer’s grey list

• Customer’s white list

• Material and designations

• Flammability of interior materials

• Documentation requirements

• Failure mode and effect analysis

• Initial sample testing of parts

• Marking

• EMC requirements

• Fogging

• Test method. Odour of trim materials in vehicles. Organic materials

• Test method, determination of formaldehyde emission from components in vehicle interiors. Organic materials

• Test method. Determination of organic emissions from non-metallic materials in vehicle interiors. Organic materials

• Device connectors

• Interface definition of Standard boxes

• ECU Power State Specification

• CAN bus technical specification

• ECU’s CAN interface test

• LIN bus technical specification

• Generic Diagnostic Specification

• ISO 16750-1: 2006

• ISO 16750-2: 2006

• ISO 16750-3: 2003

• ISO 16750-4: 2006

• ISO 16750-5: 2003 Road vehicles – Environmental conditions and testing for electrical and electronic equipment

• ISO 20653 Degrees of protection 2004-06-19

• UL94V Fire resistance 5

• ISO 3795 Determination of burning behaviour of interior materials for road vehicles

• FMVSS 302 Flammability of materials used in the occupant compartments of motor vehicles

• GADSL Global Automotive Declarable Substance List

Customer Requirements - CDML example

>1000 pages of documentation


Electrical Requirements – Power Supply

• Nominal Operating Voltage (ex. 8-13.2-16V)

• Quiescent current

• Power budget and sleep modes

• Ground offset

• Reverse battery connection

• Quick charge/jump start


Electrical Requirements – Power Supply

• Micro cut-offs


Environmental Requirements

• Mechanical– Device geometry

– Vibration loading with superimposed temperature

– Shock test

– Drop test– Stone chip test

• Climatic– Temperature range– Stepper temperature test

– Dewing test

– Change of temperature test

– Thermal shock test– Dust test

– Spraying water test

– Hot water jet test

– Immersion test

– Noxious gas test– Salt spray test

• Chemical– Chemical resitance (fuel, diesel fuel, engine oil, breake fluid, white-spirit, etc.)– Burning behavior

– UV-Light resistance

– Ozone resistance


Delphi Design Standards

• Know-how and good design practices collection– Cannot find this information on the web or books

– Gather by long experience in automotive electronics

• Sharing design tips & hints among engineers before project starts

• Avoid common problems and pitfalls (especially for inexperienced engineers)

• Examples– DDS45, Termination of Unused Pins

– DDS27, Printed Circuit Board Design Standards


Design Work Products

• Block diagram– Complex device partitioning onto

basic, functional blocks

– High-level device architecture

– Easy understanding and better job

planning

• Power dissipation diagram– Power dissipation estimations

– Manage and optimize multi-

voltage power supplies (e.g.

+3V3, +5V, +1V8, +5VSTB)

• Detailed schematics


Design Work Products (cont’d)

• Thermal simulation– Identify thermal issues (hot spots) before PCB design and proto build

• Floor plan– Guidelines to ECAD for component placement (e.g. group voltage

regulators, separate analog vs. digital circuitry)

– Layer stack allocation (signal layers, ground planes, power supply

planes, etc.)

• Electrical simulations and analysis– Determine and document sub-circuit characteristics before build (incl.

component tolerances)

– Verify sub-circuits concept



• Documentation– Performance Document

» Hardware description and its basic functions and

implementation

– Performance Verification Document

» Product electrical characteristics with tolerances (e.g.

current consumption, oscillator start-up time, etc.)



• DFMEA– How failure impacts product behavior?

– What’s failure severity?

– If failure exist what’s occurrence?


Tolerance Analysis Methods

Worst Case Stack up Root Sum Squares Monte Carlo

Pro’s + Typically the fastest and easiest method

+ Leads to a very robust design

+ Yields a much more realistic result than WC.

+ Runs faster than MC

+ Sensitivity info.

+ Yields a much more realistic result than WC.

+ More accurate than RSS if input distributions are non-normal or component interactions exist

Con’s - Results in a very conservative, possibly unrealistic result.

- There is some risk that in-coming part distributions will be very abnormal resulting in

production problems

- There is some risk that in-coming part distributions will be very abnormal resulting in

production problems- Most computation required- Because random trials are involved, results not exact.

68.27 % of the data lies within ± 1 s of the mean95.45 % of the data lies within ± 2 s of the mean99.73 % of the data lies within ± 3 s of the mean99.9937 % of the data lies within ± 4 s of the mean

99.999943% of the data lies within ± 5 s of the mean99.99999980% of the data lies within ± 6 s of the mean

VOC

LSLUSLTarget

VOP

BadBad

Good

Good


Product Mission and Reliability

1%100+80...+857

3%300+70...+806

6%700+60...+705

8%900+50...+604

24%2900+40...+503

54%6500+20...+402

5%600-20...+201

Relative

time [%]Time [h]Temperature range [C]#

CalculationIEC/TR 62380:2004

MIL-STD

MTBF

Expected

device lifetime

EBOM

&

Work conditions

Component

reliability data

4Nbr of "cold' cranks per day6

20Nbr of cranks per day5

4hDaily usage4

30km/hAverage speed3

120kmDaily mileage2

25000kmYearly mileage1

ValueParameter#


Component Selection

• AEC-Q100 qualification– Established by Chrysler, Ford, and GM (Automotive Electronics Council)

– Common part-qualification and quality-system standards for reliable, high quality electronic components

– Parts compliant with AEC-Q100 for use in the harsh automotive environment

• Component Engineering organization– Guards the proper quality of new components being introduced to Delphi

Component Database

– Helps to find cost effective equivalents

• EBOM optimization (Electrical Bill Of Material)– Review of EBOM to commonize used components

» Example: origin design: 10 x 10k + 1 x11K, can we use 11x 10k

– Avoid components obsolescence

Why?

For money...


PCB Layout

• Transfer idea from schematic onto copper substrate– Right component placement

– Proper tracks and vias sizing

• Mechanical dimensions, shape and fixation

• Heatsink and thermal management

• Follow EMC/ESD compliance good practices

• Ensure manufacturability and testability (follow DDS)– Examples:

» 100% nets with test points

» Fiducials for optical alignment


Verification

• Why?– Avoid design mistakes carry over to next stage

• Simulation and analysis• Peer review

– Experts meeting to discover potential issues and/or question particular solutions

• Design checklist• Prototype build and start-up

– Confirm concept works and meets requirements

– Provide development platform to software developers


Validation

• Design Validation (DV)– Proof model and concept

– Explore potential design weaknesses

• Product Validation (PV)– Check on final product

– Tested samples from target production line

• Generic test scope– Temperature an humidity ageing

– Temperature shocks

– Vibration

– Fatigue

• Evaluation criteria– Visual inspection

– Electrical and physical characteristics measurement

– Functional checks


Q&A


Immunity/Susceptibility- level of robustness against the influence of electromagnetic energy

Emission- discharge of electromagnetic energy

Electromagnetic

Compatibility

Immunity

Conducted Immunity(CI)

ISO 7637-2

ISO 7637-3

RadiatedImmunity(RI)

ISO 11452-2

ISO 11452-4

Emissions

RadiatedEmissions(RE)

CISPR-25

ConductedEmissions(CE)

CISPR-25

ESD

ISO 10605

Electrical Requirements – EMC Tree of Disciplines


Electrical Requirements – EMC – Classifications

Comfort and Convenience: in-car entertainment (ICE), HVAC, telematics

(satellite-navigation, phone-kit), instrument illumination, auto dimming mirrorsII

Powertrain and Safety: engine management unit (EMU), ABS, SRS,

immobiliser,body control modules (BCM), exterior lighting, central locking, wiper

controls

I

Typical In-Vehicle ApplicationsApplication Group

Application Classifications

Failure Mode Severity Classification

One or more functions of a device or system do not perform as designed during

exposure but return automatically to normal operation after exposure is removed.C

all functions of a device or system perform as designed during and after

exposure to interference.A

DescriptionClassification


Electrical Requirements – Radiated Immunity

DUTSimu lato r

XM IT

Antenna

Non-Anechoic (Reverberant) Sh ie lded Room

Mode-Stirrer

1m harness

RCV Antenna

Monitor

Probe

Injection

Probe

Ground Plane

DUT Simulator / Loads

RF

GeneratorRF

Amplifier

Closed-Loop

Method

•BCI method

•Antenna method


Electrical Requirements – Conducted Immunity

• Test Pulse 1: transients due to supply disconnection from inductive loads It influences devices

which remain connected directly in parallel with the inductance

DUT

Switch

Power

Supply

Inductive load Load



• Test Pulse 2a: transients due to sudden interruption of currents in a device connected in parallel with the device under test due to the inductance of the wiring harness

DUT

Switch

Power

Supply

Harness (Inductive)

Load



• Test Pulse 2b: simulates transients from dc motors acting as generators after the ignition is switched off

DUT

Switch

Power

Supply

Harness (Inductive)

DC

MotorV

10 %

0,9 UA

t 6

t

0 V

UA

US

t

t

d

r1 ms ± 0,5 mst6

1 ms ± 0,5 mstr

1 ms ± 0,5 mst12

0,2 s to 2 std

0 Ω to 0,05 ΩRi

20 V10 VUs

24 V system12 V systemParameters



• Test Pulses 3a, 3b: transients, which occur as a result of the switching processes. The characteristics of these

transients are influenced by distributed capacitance and inductance of the wiring harness

DUT

Switch

Power

Supply Inductive load

Wiring harness with distributed inductance and capacitance



• Test Pulse 4: simulates supply voltage reduction caused by energising the starter-motor circuits of internal combustion engines, excluding spikes associated with starting

DUT

Switch

Power

Supply

Starter

Motor

Default values Umin and Ustart are respectively 4.9 V and 6.5 V for the 12 V powernet and 18 V and21 V for the 42 V powernets



• Test Pulse 5: load dump transient occurring in the event of a discharged battery being disconnected while the alternator is generating charging current with other loads remaining on the alternator circuit at this moment

DUT

Deffective connection

Power

Supply

LoadAlternator


Electrical Requirements – ESD


Electrical Requirements – Conducted EmissionB a t te r y

I n - l in e f u s e

L in e Im p e d a n c e S ta b i l iz a t io n N e tw o r k ( L I S N )

R e la y

D U T

O p t io n a l C u r r e n t

P r o b e

5 0 o h m t e rm in a t io n

A voltage probe is used to record the

transient pulse produced by the DUT

when a relay contact is opened.

The DUT is connected through

the LISN to isolate the

battery’s ability to filter the

transient.


Electrical Requirements – Radiated Emission


References

1. International Organization for Standardization official WEB http://www.iso.org/iso/home.htm

2. Wikipedia : http://en.wikipedia.org

3. IEEE Std. 1042-1987 IEEE Guide to Software Configuration Management http://ieeexplore.ieee.org/

4. Automotive Electronics Council http://www.aecouncil.com/

5. Automotive EMC http://www.autoemc.net/

6. Volvo Group Suppliers Portal http://www.volvo.com/suppliers/global/en-gb/supplierapplication/standardsaccess/standards.htm

7. PSA GENERAL TECHNICAL SPECIFICATIONS B217110